German chamomile (Matricaria recutita, also known as Matricaria chamomilla or Chamomilla recutita) is one of the best-known medicinal herbs in the world. Ivan Salamon, from the University of Presov in Slovakia, also calls it “one of the most well-documented,” and points to its use in the official dispensaries of over 26 countries.1 Dr. Salamon has spent much of his research career on this beautiful and delicate plant, documenting changes in its volatile oil profile in different growing environments,2 analyzing chamomile crops grown in the open in Slovakia for contamination (and found them to contain very low levels of heavy metals, pesticide and radioactivity residue),3 even helping to develop a specialized industrial-scale harvester for the flowers.4 In his review of the medicinal properties of chamomile, he notes its consistent popularity and effectiveness.
We think of chamomile flowers (the most active medicinal part) as having good antispasmodic action,5 which may be part of the reason why so many people use this plant to help with occasional mild anxiety and stress, 6 or for digestive complaints:7 an antispasmodic effect contributes to relaxation and to its soothing effects. It doesn’t hurt that chamomile flowers act as gentle bitters, too: steep them for more than a minute or two, and the tea goes from buttery and floral to noticeably bitter. This allows chamomile to hold some of the benefits of bitters, too – and these benefits come out when the flowers are steeped for a few weeks in alcohol to make tinctures. The richness of chamomile’s flavor comes from a complex chemical profile, that includes the luscious volatile oils such as farnesol, bisabolol, and chamazulene, but also bitter flavonoids and organic acids such as apigenin, quercetin and chlorogenic acid.8
But what about safety concerns? Can chamomile be used safely, long-term, by the general population? What about children? Can you use chamomile in pregnancy? Because of its popularity, many individuals have consumed this plant and had opportunities to record adverse events or reactions. Many have also participated in retrospective analyses documenting herbal use in pregnancy. Let’s take a look.
First off, regarding chamomile’s overall safety, the major concern is around folks who have allergic reactions to pollen from flowers in the daisy family, the Asteraceae. Ragweed is an example of one of these plants, though if you’re sensitive to ragweed it doesn’t mean you will be allergic to chamomile – but in some very limited cases, there have been reports of allergic reactions to ingesting the flowers of chamomile,9 and also some topical irritation on the skin in isolated cases. Notably, there are very few reports of these types of reactions, considering the widespread use of chamomile. Nevertheless, we always suggest trying a very small amount of chamomile tea or extract on your skin, then a small sip in the mouth, the first time you explore using this plant.
Chamomile flowers don’t seem to bioaccumulate toxic substances, including heavy metals, from the soil or the air very easily. Dr. Salamon again investigated this, by growing the herb in soils artificially enriched with high quantities of heavy metals, including lead, cadmium, and nickel. While the roots, and to a certain extent the leaves, did take up some of the contamination, the flowers had very low levels (still meeting WHO and EU contaminant guidelines) despite being grown in such poor conditions.10 It is reassuring to see that, even in a worst-case scenario, chamomile flowers remained relatively free of contamination.
There have been some concerns expressed about the use of chamomile alongside blood-thinning drugs such as warfarin. This concern has not been borne out in clinical settings, with the exception of one isolated case of a 70-year-old woman on warfarin11 who used chamomile tea and body lotion at the same time. She showed signs of poor blood clotting – but even the researchers investigating the case weren’t sure if the chamomile was to blame.12 In the case of chamomile and blood thinners, this report might just be the exception that proves the rule: given its widespread use, it is remarkable that this is the only instance of even a potential interaction. Nevertheless, if you are taking prescription medications, it is always a good policy to discuss the use of any medicinal plants with your physician.
Numerous clinical trials have observed children taking chamomile,13 and as expected, the herb continues to show an exceptional safety profile, with few if any adverse events ever reported (and if they are, they tend to be mild and transient). Similarly, when it comes to using chamomile in pregnancy, all available evidence points to an excellent safety record. First off, animal models found that chamomile did not cause damage to the developing fetus, nor increase the rate of birth defects or spontaneous abortions, even at very high doses.14 But more interestingly, large studies that examined populations of pregnant women to understand what types of herbs they were using consistently found that chamomile was right at the top of expectant mothers’ list. A comprehensive review from 2016 listed chamomile as an herb “considered safe in pregnancy” (alongside cranberry, ginger, Echinacea, and raspberry leaf).15 In 2009, a questionnaire sent out to over 8,500 women in Quebec identified chamomile again as one of the top herbs used in pregnancy, and uncovered no reported adverse events on mother or fetus.16 In 2011, an even larger analysis looked at over 14,000 women in the United Kingdom, and found chamomile to be the most-used herb among pregnant mothers. Its use peaked in the third trimester (though women used it throughout their pregnancy), mostly for its gentle relaxing effect, to support digestion, and to relieve occasional nausea.17 The study’s authors concluded that, based on the effectiveness and safety of the herbs used by pregnant women, interventions such as chamomile in pregnancy are valuable “as part of a self care approach which could be encouraged in a modern and sustainable health care system.” We couldn’t agree more.
1. Salamon, Ivan. "Chamomile: a medicinal plant." The Herb, spice and medicinal plant digest (1992). Published for the Food and Agriculture Organization (FAO) of the United Nations.
2. Salamon, I. "Effect of the internal and external factors on yield and qualitative-quantitative characteristics of chamomile essential oil." I International Symposium on Chamomile Research, Development and Production 749. 2006.
3. Salamon, I., P. Labun, and P. Petruska. "Occurrence of Heavy Metals, Radioactivity, and Pesticide Residues in Raw Materials of Elderberry and Other Herbs and Fruits in Slovak Republic." I International Symposium on Elderberry 1061. 2013.
4. https://www.researchgate.net/publication/304570701_The_Chamomile_Harvest_Season_20152016_the_new_unique_multifuncion_CHAMOMILE_HARVESTER Accessed 26 May 2017
5. Mehmood, Malik Hassan, et al. "Antidiarrhoeal, antisecretory and antispasmodic activities of Matricaria chamomilla are mediated predominantly through K+-channels activation." BMC complementary and alternative medicine 15.1 (2015): 75.
6. Amsterdam, Jay D., et al. "A randomized, double-blind, placebo-controlled trial of oral Matricaria recutita (chamomile) extract therapy of generalized anxiety disorder." Journal of clinical psychopharmacology 29.4 (2009): 378.
7. Becker, Brigitta, Ulrike Kuhn, and Bettina Hardewig-Budny. "Double-blind, randomized evaluation of clinical efficacy and tolerability of an apple pectin-chamomile extract in children with unspecific diarrhea." Arzneimittelforschung 56.06 (2006): 387-393.
8. World Health Organization. WHO monographs on selected medicinal plants. Vol. 1. World Health Organization, 1999.
9. Subiza, Javier, et al. "Anaphylactic reaction after the ingestion of chamomile tea: a study of cross-reactivity with other composite pollens." Journal of allergy and clinical immunology 84.3 (1989): 353-358.
10. Salamon, I., et al. "Cadmium, lead and nickel accumulation in chamomile plants grown on heavy metal-enriched soil." I International Symposium on Chamomile Research, Development and Production 749. 2006.
11. Saw, Jun Tze, et al. "Potential drug–herb interaction with antiplatelet/anticoagulant drugs." Complementary therapies in clinical practice 12.4 (2006): 236-241.
12. Segal, Robert, and Louise Pilote. "Warfarin interaction with Matricaria chamomilla." Canadian Medical Association Journal 174.9 (2006): 1281-1282.
13. Becker, Brigitta, Ulrike Kuhn, and Bettina Hardewig-Budny. "Double-blind, randomized evaluation of clinical efficacy and tolerability of an apple pectin-chamomile extract in children with unspecific diarrhea." Arzneimittelforschung 56.06 (2006): 387-393.
Sharifi, Hosein, et al. "Topical use of Matricaria recutita L (Chamomile) Oil in the Treatment of Monosymptomatic Enuresis in Children A Double-Blind Randomized Controlled Trial." Journal of evidence-based complementary & alternative medicine 22.1 (2017): 12-17.
Gardiner, Paula, and Kathi J. Kemper. "Insomnia: Herbal and dietary alternatives to counting sheep; Parents are turning to herbs and dietary supplements to treat problems their children have falling and staying asleep. Do these products work? Are they risky?." Contemporary Pediatrics 19.2 (2002): 69-78.
Hanson, Ellen, et al. "Use of complementary and alternative medicine among children diagnosed with autism spectrum disorder." Journal of autism and developmental disorders 37.4 (2007): 628-636.
14. Leslie, G. B., and G. Salmon. "Repeated dose toxicity studies and reproductive studies on nine Bio-Strath herbal remedies." Swiss medicine 1 (1979): 1-3.
Namjooyan, F., et al. "Effect of Matricaria chamomilla L. extract on fetal absorption, placenta structure and liver of diabetic pregnant rats." Planta Medica 77.12 (2011): PM184.
15. Jaafari, Mahdieh, et al. "Herbal medicine in pregnancy." Advanced Herbal Medicine 2.1 (2016): 54-66.
16. Moussally, Krystel, Driss Oraichi, and Anick Bérard. "Herbal products use during pregnancy: prevalence and predictors." Pharmacoepidemiology and drug safety 18.6 (2009): 454-461.
17. Bishop, Jackie L., et al. "The use of complementary and alternative medicine in pregnancy: data from the Avon Longitudinal Study of Parents and Children (ALSPAC)." Complementary therapies in medicine 19.6 (2011): 303-310.
